Edward hett



UNITED STATES PATENT OFFICE. v

EDWARD HETT, OF NEW YORK, N. Y.

METHOD OF TREATING PRINTING-SURFACES.

SPECIFICATION forming part of Letters Patent No. 637,588, dated November 21, 1899,

Application filed October 21, 1899- Serial No. 734,378. [No specimens) To all whmn it may concern:

. Be it known that I, EDWARD I-IETT, a citizen of the United States, and a resident of New York, (New Dorp,) county of Richmond, State of New York, have invented an Improved Method of Treating Printing Surfaces, of which the following is a specification.

This invention relates to a novel method whereby a prepared lithographic surface may be preserved indefinitely and made ready for subsequent use in printing with a colored ink without the necessity of additional treatment preparatory to applying said colored ink.

The invention consists of the method hereinafter set forth, and specified in the claims.

Heretofore after a lithographic printing surface has been prepared and rolled up it has been the practice to leave the rolling-up ink upon the printing-surface for the purpose of preserving the printing-surface until it is about to be inked with the printing-ink and employed in printing, and this is especially important when the prepared printing-surface is not to be immediately used in printing, but is to be stored away for a time. The preserving-ink employed for this purpose has generally been the ordinary black ink used in rolling up the printing-surface. Before inking the printing-surface with a colored printing-ink it has been the practice to first wash oif the black preserving-ink in order that when the colored printing-ink is applied to the printing-surface the previously-applied black preserving-ink might not be left to detract from the tone of the colored printingink and so spoil a number of copies of the printed matter. In washing off the black preserving and rolling-up ink before applying the colored ink considerable time has been consumed. The time thus consumed in washing off the black preserving-ink in multicolorprinting diminishes greatly the earning capacity of the press, and thus adds to the expense, and this expense increases in proportion to the number of printing-surfaces which the particular job requires. In carrying out my method I apply to the printing-surface a suitable light-colored body adapted to pre-- serve from deterioration the prepared printing-surface between the time when the prepared printing-surface is prepared and the time when the said printing-surface is inked a body of such'color being best adapted to 1 accomplish its purpose in connection with a greater number of colored printing-inks than a body of any other color.

form, so that it may be more readily applied to the prepared printing-surface and so that it may be applied by means of inking-rollers. The preserving body which I find most suitable for the purpose consists of one part zincwhite, two parts Vaseline, two parts magnesia or laketine, and a small quantity of linseedoil. A preserving body thus constituted forms what may be termed a white ink.

When a preserving body has been applied to the printing-surface, the colored printingink may be applied to this printing-surface without previously treating the printing-surface to remove the preserving body, and the preserving body thus left will not materially detract from the color tone of the printing ink subsequently applied. In using the lightcolored body whose constituents are above specified it will be found that it blends with the printing-ink, and whatever preserving body is employed it is preferred that it be of such a character that this blending action will take place, because it is believed that all traces of the preserving body will thus most quickly disappear in the printed copies.

The term lithographic is herein used in its broader significance and without reference to whether the printing-surface is stone, zinc, aluminium, or other material the printing with which is dependent upon the mutuallyrepelling properties of grease and water.

What I claim as new, and desire to secure by Letters Patent, is

1. The method of preserving and making a This light-col ored preserving body is preferably in fluid prepared lithographic-printing surface ready for the reception of a colored printing-ink Without the necessity of additional treatment preparatory to applying said printing-ink, which consists in applying to said prepared printing-surface a suitable light-colored body adapted to preserve from deterioration the prepared printing-surface between the time when said printing-surface is prepared, and the time when said printing-surface is inked for printing, said body being of such a character that when the printing-ink is applied the body does not materially detract from the color tone of said printing-ink.

2. The method of preserving and making a prepared lithographic-printing surface ready for the reception of a colored printing-ink Without the necessity of additional treatment preparatory to applying said printing-ink,

terially detract from the color tone of the printing-ink,

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EDWARD HETT} Witnesses:

J. O. GEMPLER, B. O. GAEDEKE. 

